Absorbable surgical sutures coated with polyoxyethylene-polyoxypropylene copolymer lubricant

Abstract

The handling characteristics, including particularly the knot run-down, of synthetic absorbable surgical sutures and tissue drag characteristics are improved by a coating of a lubricating film of a bioabsorbable copolymer having polyoxyethylene blocks and polyoxypropylene blocks, and which bioabsorbable copolymer has a molecular weight such that it is pasty to solid at 25° C.

We claim: 
     
       1. An absorbable surgical suture having improved knot run-down characteristics and reduced tissue drag comprising a polyfilamentary synthetic absorbable polymer strand having thereon a thin lubricating coating of a lubricating absorbable copolymer comprising polyoxyethylene blocks and polyoxypropylene blocks to aid run-down and handleability, said bioabsorbable copolymer having a molecular weight such that it is pasty to solid at 25° C. 
     
     
       2. The suture of claim 1 in which the lubricating bioabsorbable polymer has the formula: ##STR6## where one of R 1  and R 2  is methyl and the other hydrogen, and n and m are sufficiently large that the compound is pasty to solid at 25° C., R is the residue of a relatively low molecular weight reactive hydrogen compound having from 2 to about 6 reactive hydrogen atoms and having not over 6 carbon atoms in said compound, and c is the number of reactive hydrogens on the compound forming R. 
     
     
       3. The suture of claim 1 in which the lubricating bioabsorbable copolymer has effectively the formula: ##STR7## where x, y and z are sufficiently large that the lubricating bioabsorbable copolymer is pasty to solid at 25° C. 
     
     
       4. The suture of claim 3 in which the lubricating bioabsorbable copolymer has a molecular weight of about 8350 and x and z are about 75 and y about 30, and the melting point is about 52° C. 
     
     
       5. The suture of claim 1 in which the lubricating bioabsorbable copolymer has effectively the formula: ##STR8## where n, m and o are sufficiently large that the lubricating bioabsorbable copolymer is pasty to solid at 25° C. 
     
     
       6. The suture of claim 1 in which the lubricating bioabsorbable copolymer has effectively the formula: ##STR9## where R 3  is ##STR10## where q and r are sufficiently large that the lubricating bioabsorbable copolymer is pasty to solid at 25° C. 
     
     
       7. The suture of claim 1 in which the synthetic absorbable polymer strand is of a tissue absorbable polymer subject to hydrolytic degradation to non-toxic tissue compatible absorbable components, and which polymer has glycolic acid ester linkages. 
     
     
       8. The suture of claim 3 in which the synthetic absorbable polymer strand is of a tissue absorbable polymer subject to hydrolytic degradation to non-toxic tissue compatible absorbable components, and which polymer has glycolic acid ester linkages. 
     
     
       9. The suture of claim 4 in which the synthetic absorbable polymer strand is of a tissue absorbable polymer subject to hydrolytic degradation to non-toxic tissue compatible absorbable components, and which polymer has glycolic acid ester linkages. 
     
     
       10. The suture of claim 7 in which the tissue absorbable polymer is polyglycolic acid. 
     
     
       11. The suture of claim 8 in which the tissue absorbable polymer is polyglycolic acid. 
     
     
       12. The suture of claim 9 in which the tissue absorbable polymer is polyglycolic acid. 
     
     
       13. The suture of claim 1 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       14. The suture of claim 2 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       15. The suture of claim 3 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       16. The suture of claim 4 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       17. The suture of claim 7 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       18. The suture of claim 8 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       19. The suture of claim 9 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       20. The suture of claim 10 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       21. The suture of claim 11 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       22. The suture of claim 12 in which the lubricating coating is about 0.1 to 25 percent by weight of the lubricating bioabsorbable copolymer of the weight of the uncoated strand forming the suture, whereby both chatter and friction are reduced sufficiently that a square knot is movable on the suture with control of a wound edge. 
     
     
       23. A method of closing a wound in living tissue which comprises: sewing edges of a wound in living tissue with the sterile absorbable surgical suture of claim 1, tying the suture into a square knot,   running down the square knot to approximate the tissues in a desired location,   placing additional throws on the square knot, and   within less than about 48 hours bioabsorbing and removing the lubricant absorbable copolymer from the suture thereby increasing knot security and,   leaving the absorbable surgical suture in living tissue until the suture strand is absorbed by living tissue during the healing process, the suture providing useful tissue retention strength for at least 15 days and absorption being substantially complete within 90 days.